Art of coloring wood.



- ammonia.

WILLIAM AUGUSTUS HALL, OF NEW YORK, N.

Y.,' ASSIGNOR .TO AMERICAN I MAHOGANY COMPANY, A CORPORATION OF MAINE.

ART OF COLORING WOOD.

Application filed May 13, 1907, Serial No. 373,229.

and of course it is very (lllIlCLlllJ to obtain lumber which is allsapor all heart. In the processes of treatin comparatively inexpensivewoods, for the urpose of securin products closely resembling the higherpriced wood, such as walnut, mahogany, etc.,.and in which processescoloring dyes alone or coloring chemicals mixed with coloring dyes areforced into and throughout the bodies of the woods, it'has heretoforebeen found impossible to obtain uniform colorsin the sap and heartportions of the woods. Where coloring solutions alone are employed thecoloring matter becomes deposited principally in the sap portions of thewoods,-so that such portions will become quite dark,

leaving the heart portions of the woods many shades lighter. When thewoods are colored by a very penetrating chemical solution, such as anammoniacal solution, it has been found that the heart portions of thewoods (being very rich in tannic ligneous matter, or ligneous mattercontaining tannin, which is acted on bytheammonia) become darkened to amuch greater extent than the saxhportions ofthe woods.

, e present invention has for its object to obviate the difficultiesabove referred to, so

as to -produce artificially colored woods in which the colors or shadeswill be substantially uniform throughout the heart and sap portionsthereof.

In carrying the invention into effect, with aweak solutlon-of ammonia(say 2 gals. of 26% ammonia'in gals. of water) is mixed a coloringmatter or dye which must either be soluble in the ammoniacal solution orbe unafi'ected by ammonia.- In other words, the coloring 'matter or dyewhich is used must not be of an acid character so as to be precipitatedfrom its solution by ammonia, nor one whose color would be destroyed byThe coloring matter or dye Specification of Letters Patent.

Patented Feb. 23, 1909. Renewed November 20, 1908. Serial No. 463,715.

which is preferred for this urpose is a wood extract, such as can beobtained from the wood or bark of trees which are rich in tannin (suchas hemlock, oak and chestnut), and a greater or less quantity of thiswood extract 13 mixed with the ammoniacal solution to produce the shadesor colors desired. r

In the is prefera ly in the form of boards, flitches or deals, the woodis first thoroughly dried, either by seasoning in the open air or bykiln dr ing, or by both. It is then preferably subjected, in a closedreceptacle, to the action of a vacuum referably above 25 inches ofmercury, and which will be sufficiently powerful and long continued toremove from the wood practically all the air therein contained, so as tomake it absorbent or receptive to the fluids to be later applied. Theammoniacal solution, with the colorin matter mixed therewith, is thenintroduce or drawn into the receptacle and a high hydraulic or airpressure (preferabl "from 300 to 800 pounds to the square inch isapplied and maintained until the wood is thoroughly impre nated throuhout.

The coloring so ution is pre erably intro duced into the closedreceptacle in a heated condition, at approximately 200 F., or is heatedto about this temperature after being introduced-into the closed recetacle. Any of the low priced woods, such as eech, birch, maple, etc. maybe treated by this process, and will be colored to a beautiful brownresembling black walnut by the ammoniacal solution with the woodextracts therein above mentioned. In forcing the solution into thewood,'by the high pressurereferred to, the artificial coloring matter islargel deposited in the sap portions .of the woo while the ammonia,having a muchhi'ghe'r capillary speed of penetration, finds its waythroughout the heart portions of the wood and colors the said heartportions a dark brown by chemical action on the wood, such coloringbeing uniform with the brown color imparted to the sap portions of thewood by the action of the ammonia with the addition of theartificialcoloring matter. 'In other words, the sap portions of the wood will belargely colored by the brown stain of theartificial coloring matter,although someprocess of treating the wood, which what colored by thechemical action of the,

wood, which contain larger proportions of ammonia; hile the heartportions of the 5 tannic ligneous matter than the sap portions of thewood, willbe wholly or principally colored by the chemical action of thehot ammonia; so that-in the resulting product the heart and sa portionsof the wood will be uniformly co ored to the same, or practically thesame, shades.

Having thus described my invention I claim and desire to secure byLetters Patent: A I

I. The herein-described process of coloring wood, consisting'm treatingthe same,

under a high pressure, with -anaqueous ammoniacal solution mixed with asuitable coloring dye.

2. The herein-described-process of coloring wood, consisting intreatingthesame,

: under a-hi h'pressure, with a hot aqueous ammoniaca coloring dye.

3. The herein-described process of coloringlwood, consisting in treatingthe same,

under a high pressure, with an aqueous ammonlacal solution 'mixed with asuitable wood extract.

4; The herein-described process of color ing wood, consisting intreating the same,

ing wood, consisting in e from the wood by a vacuunniprocess to ren-'solution mixed with a suitable 1 rocess of color the said solution andwhich is not injurable' by ammonia.

6.The herein-described rocess of coloring wood, consisting in exhaustingthe air from the wood by a vacuum rocess to render the wood absorbent,an then treating the same, under a high ressure, with a hot aqueousammonia-cal so ution containing a suitable coloring matter which issoluble in the said solution'and which is not injurable by ammonia.

7. The herein-described rocess of colorder the wood absorbent, an thentreating the same, under a. high pressure, with an aqueous ammoniacalsolution containing a suitable colormg matter which 1s soluble 1n thesaid solution'and which is unaffected by ammonia, such coloring matterconslstlng of a wood extract, as hereinbefore described.

8. The herein-described process of coloring wood, consisting inexhausting the air from the wood-by a vacuum process to render the woodabsorbent, and thentreating the same, under a'hi 'h pressure, with a hotaqueous ammoniaca solution containing a suitable coloring matter whichis soluble in the said 1 solution and which is unaffected by 1111-monla, such coloring matter consistlng of a wood'extract, ashereinbefore described.

Irf testimony whereofiI aflix my signature,

in presence of two witnesses.

WILLIAM AUGUSTUS Witnesses:

JOHN C. MoCUsKER, O. M. SWEENEY.

HALL.

austing the air

